The documentation is loosely based on the man pages of the OpenGL Sample
Implemenation from SGI, see: http://oss.sgi.com/projects/ogl-sample/. It is
used under the SGI Free Software License B. This license requires the
following notice:

License Applicability. Except to the extent portions of this file are made
subject to an alternative license as permitted in the SGI Free Software
License B, Version 1.1 (the "License"), the contents of this file are
subject only to the provisions of the License. You may not use this file
except in compliance with the License. You may obtain a copy of the License
at Silicon Graphics, Inc., attn: Legal Services, 1600 Amphitheatre Parkway,
Mountain View, CA 94043-1351, or at: http://oss.sgi.com/projects/FreeB/.

Note that, as provided in the License, the Software is distributed on an "AS
IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A PARTICULAR
PURPOSE, AND NON-INFRINGEMENT.

Original Code. The Original Code is: OpenGL Sample Implementation, Version
1.2.1, released January 26, 2000, developed by Silicon Graphics, Inc. The
Original Code is Copyright (c) 1991-2002 Silicon Graphics, Inc. Copyright in
any portions created by third parties is as indicated elsewhere herein. All
Rights Reserved.